For the next millennium, the 5th, it is customary to speak in
terms of various "cultures" or "horizons"
distinguished in general by the pottery, which
may be classed by its colour, shape,
hardness, and, above all, by its decoration.
The name of each horizon is derived either from
the type site or from the place where the pottery was first
found: Samarra' on the Tigris, Tall
Halaf in the central Jazirah, Hassuna
Level V, Al-'Ubaid near Ur,
and Hajj Muhammad on the Euphrates,
not far from As-Samawah (some 150 miles
south-southeast of Baghdad).

Along with the improvement of tools, the
first evidence for water transport (a model boat
from the prehistoric cemetery at Eridu, in the
extreme south of Mesopotamia, c. 4000 BC), and
the development of terra-cottas, the most
impressive sign of progress is the constantly accelerating
advance in architecture. This can best be
followed in the city of Eridu, which in
historical times was the centre of the cult of the Sumerian
god Enki.

Originally a small, single-roomed shrine, the temple in the Ubaid
period consisted of a rectangular building, measuring 80 by 40
feet, that stood on an artificial terrace. It had an "offering
table" and an "altar"
against the short walls, aisles down each side, and a facade
decorated with niches. This temple,
standing on a terrace probably originally designed to protect the
building from flooding, is usually considered
the prototype of the characteristic religious structure of later Babylonia,
the ziggurat.

The temple at Eridu is in the very same place
as that on which the Enki ziggurat stood in the
time of the 3rd dynasty of Ur (c. 2112-c. 2004
BC), so the cult tradition must have existed on the same spot for
at least 1,500 to 2,000 years before Ur III
itself. Remarkable as this is, however, it is not justifiable to
assume a continuous ethnic tradition. The
flowering of architecture reached its peak with the great temples
(or assembly halls?) of Uruk, built around the
turn of the 4th to 3rd millennium BC (Uruk
Levels VI to IV).

In extracting information as to the expression of mind and
spirit during the six millennia preceding the invention
of writing, it is necessary to take account of four
major sources: decoration on pottery, the care
of the dead, sculpture, and the designs
on seals.There is, of course, no justification in
assuming any association with ethnic groups.

The most varied of these means of expression is undoubtedly
the decoration of pottery. It is hardly
coincidental that, in regions in which writing
had developed, high-quality painted pottery was
no longer made. The motifs in decoration are either abstract
and geometric or figured,
although there is also a strong tendency to geometric
stylization. An important question is the extent to
which the presence of symbols, such as the bucranium
(a sculptured ornament representing an ox skull), can be
considered as expressions of specific religious ideas,
such as a bull cult, and, indeed, how much the
decoration was intended to convey meaning at all.

It is not known how ancient is the custom of burying
the dead in graves nor whether its intention was to
maintain communication (by the cult of the dead) or to guard
against the demonic power of the unburied dead
left free to wander. A cemetery, or collection
of burials associated with grave goods, is first
attested at Zawi Chemi Shanidar.

The presence of pots in the grave indicates that the bodily
needs of the dead person were provided for, and the
discovery of the skeleton of a dog and of a
model boat in the cemetery at Eridu
suggests that it was believed that the activities of life could
be pursued in the afterlife.

The earliest sculpture takes the form of very crudely worked terra-cotta
representations of women; the Ubaid
Horizon, however, has figurines of both
women and men, with very
slender bodies, protruding features, arms akimbo, and the
genitals accurately indicated, and also of women suckling
children. It is uncertain whether it is correct to describe these
statuettes as idols, whether the figures were cult
objects, such as votive offerings, or
whether they had a magical significance, such as
fertility charms, or, indeed, what purpose they
did fulfill.

Seals are first attested in the form of stamp
seals at Tepe Gawra, north of Mosul.
Geometric designs are found earlier than scenes with figures,
such as men, animals, conflict
between animals, copulation, or dance.
Here again it is uncertain whether the scenes are intended to
convey a deeper meaning. Nevertheless, unlike pottery,
a seal has a direct relationship to a particular
individual or group, for the seal
identifies what it is used to seal (a vessel, sack, or other
container) as the property or responsibility of a specific
person. To that extent, seals represent the earliest pictorial
representations of persons. The area of distribution of the stamp
seal was northern Mesopotamia, Anatolia,
and Iran. Southern Mesopotamia,
on the other hand, was the home of the cylinder seal,
which was either an independent invention or was
derived from stamp seals engraved on two faces.
The cylinder seal, with its greater surface area
and more practical application, remained in use into the 1st
millennium BC. Because of the continuous changes in the style of
the seal designs, cylinder seals are among the
most valuable of chronological indicators for
archaeologists.

In general, the prehistory of Mesopotamia can
only be described by listing and comparing human achievements,
not by recounting the interaction of individuals or peoples.
There is no basis for reconstructing the movements and migrations
of peoples unless one is prepared to equate the spread of
particular archaeological types with the extent of a particular
population, the change of types with a change of population, or
the appearance of new types with an immigration.

The only certain evidence for the movement of peoples beyond
their own territorial limits is provided at first by material
finds that are not indigenous. The discovery of obsidian
and lapis lazuli at sites in Mesopotamia
or in its neighbouring lands is evidence for the existence of trade,
whether consisting of direct caravan trade or of
a succession of intermediate stages.

Just as no ethnic identity is recognizable,
so nothing is known of the social organization of
prehistoric settlements. It is not possible to
deduce anything of the "government" in
a village nor of any supraregional connections
that may have existed under the domination of one centre.
Constructions that could only have been accomplished by the
organization of workers in large numbers are first found in Uruk
Levels VI to IV: the dimensions
of these buildings suggest that they were intended for gatherings
of hundreds of people. As for artificial irrigation,
which was indispensable for agriculture in south
Mesopotamia, the earliest form was probably not the irrigation
canal. It is assumed that at first floodwater was dammed
up to collect in basins, near which the fields
were located. Canals, which led the water
farther from the river, would have become necessary when the land
in the vicinity of the river could no longer supply the needs of
the population.